1. Field of the Invention
The subject invention relates to a hydraulic power unit for supplying hydraulic fluid to various hydraulic devices that control hydraulic fluid pressure, velocity, and direction.
2. Description of the Prior Art
Various assemblies are used to deliver hydraulic fluid from a tank to hydraulic devices. Most assemblies include a tank having a bottom and a peripheral side wall extending upwardly from the bottom to a top opening for defining a chamber for containing fluid. The assembly further includes a motor, a first pump having a first inlet and a first outlet, a drive interconnecting the motor and the first pump, a fluid distribution manifold, and a fluid line interconnecting the pump first outlet and the manifold for conveying fluid from the first outlet to the manifold.
However, these assemblies are very large and occupy a large amount of space, which may be limited in factories and work spaces. Additionally, these assemblies require the entire system to be shut down for minor repairs and do not provide for easily removal of the components such as the pump. These assemblies are not interchangeable with different assemblies and are designed to interact only with their specific assembly and can not be expanded to fit differently sized tanks.
There are removable assemblies which allow for easy access and repair. One such assembly is shown in U.S. Pat. No. 5,553,794 to Oliver et al. The ""794 Patent discloses a pump system being disposed within a tank. The pump system comprises a pump housing, a removable top, and a pump motor having a shaft that extends through an opening. The pump housing is attached to the removable top and houses a pump that is connected to the shaft. When the pump motor is operated, the shaft rotates and operates the pump. The pump system also includes a liquid level detector having three positions. When the highest position is reached, the pump is operated to lower the level inside the tank.
However, one disadvantage is there is no way to ensure that the pump is operating efficiently. The entire assembly must be shut down and taken apart in order for the pump to be tested to determine if the pump is operating efficiently.
The subject invention provides a hydraulic power assembly comprising a tank having a bottom and a peripheral side wall extending upwardly from the bottom to a top opening for defining a chamber for containing hydraulic fluid and a removable top disposed over the top opening to close the chamber. A motor is disposed on the removable top outside the chamber and a drive is in sealing engagement with the removable top to connect the motor and a first pump having a first inlet and a first outlet depending from the removable top and into the chamber. A fluid distribution manifold is also disposed on the removable top out side the chamber and a fluid line interconnects the pump outlet and the manifold for conveying fluid from the outlet to the manifold.
Accordingly, the invention provides a compact and modular hydraulic unit wherein the components are supported by a removable top and wherein the removable top may be multiplied to increase the capacity of a hydraulic unit by merely adding additional tops with the components supported thereon. Additionally, the removable top being removable from the tank allows easy access to repair and replace the pumps without having to drain the hydraulic fluid from the tank.